FORT OF THE DRAGON EGG WARMER

By Marta Zinicheva, Sanjana Patel, Sibora Sokolaj

For our useless machine assignment, we built an egg wrapping device, which deploys a temperature sensor to evaluate weather conditions. If the temperature falls below 20 degrees, the device starts to wrap around an egg seated on a royal throne with a piece of fabric. The device includes a system of two gears and a stepper motor to initiate movement. The theme of our project is centered around game of thrones, which is referenced throughout our video and the aesthetic design of our machine.

Mechanical Parts:
2 gears (laser cut plywood)

Uln2003 stepper motor

Arduino breadboard and wires

USB cord

Temperature sensor LM35

Furniture:

4 Corinthian columns (plywood)

Table (plywood)

Throne (plywood)

Fabric curtain Egg (plastic)

Supporting elements:

6 plastic columns 6mm Rail (plywood)

Vertical wall (plywood)

Horizontal base, 2 levels (plywood)

Equipment used:

Band saw

Table saw

Laser cutter

Initially, our design was wrapping yarn around the egg by passing it through the hollow Plexiglas tube and then being lifted up and down.

However, the mechanism to stir the tube was too complex and required a lot of calibration so that if parts did not line up exactly right, and the 2 driver motors did not reverse direction at the correct time, the stir stick did not complete the full rotation. The stirring mechanism was simplified to 2 gears without any links and this made it possible for the machine to rotate correctly. The lifting mechanism was also eliminated as it risked moving the stirring stick of the extreme center of the track it is following and having it get stuck. To get a full enclosure for the egg fort, yarn was switched out with a fabric sheet. This way, the fort could be constructed with one full rotation of the stirring stick.

In the course of this assignment, we have further familiarized ourselves with the process of building and programming a machine. We have decided to take on the challenge of designing our own unique mechanism starting from 3D-modelling, designing individual elements and linking them together in one system. We have also dedicated a large portion of our design process to the aesthetic design of our machine, which would emphasize its “uselessness” by introducing some elements with excessive exuberance such as Corinthian columns and a royal throne. Throughout the process, we have encountered numerous challenges such as transitioning our model form the 3D realm into the physical world. This required us to calibrate and modify parts of our machine to minimize the effects of gravity, friction, and account for tolerance. Selecting the appropriate scale and materials presented its own difficulties as our structure had to be lightweight enough for the motors to be able to move it, yet slick enough to reduce friction. Due to our previous rather unsuccessful experience with using plexi as a material, we leaned towards using wood instead. This has allowed us to have stronger connections between parts but resulted in increased friction which slowed down the movement of the component moving the fabric in our design. As part of our reflection, we also learned that a reduced scale would be more appropriate since the stepper motor that we used could supply limited power, slightly below desired. As a result, although we believe that our machine could still be improved and perfected, we have been able to achieve what we have envisioned and to build a working mechanism serving its rather “useless” purpose.